This invention relates to an air intake device for an engine and more particularly to an improved, compact and yet high capacity air intake device for an engine.
As is well known, an internal combustion engine requires copious amounts of air during its operation. This is particularly true with respect to the induction system for the engine, since as is well known, the output of the engine depends directly upon its ability to induct air. Although the principle is well known, the capability of providing adequate air flow to the engine for high power outputs is a more difficult problem in practice. This is particularly true in conjunction with outboard motors, wherein the overall configuration of the power head should be kept as small and as compact as possible for obvious reasons.
In outboard motors employing V-type engines and operating on the crankcase compression, two-cycle principle, it is a common practice to provide an individual carburetor or carburetor barrel for each crankcase chamber. Frequently, these carburetors are disposed at an angle corrsponding to the angle between the cylinder banks. Normally, the induction system and carburetors are disposed at the forward end of the power head and it is desirable to keep the transverse width of the power head small for streamlining and appearance purposes. However, it is also necessary to provide some form of air intake device for collecting air from within the protective cowling of the outboard motor and delivering it to the induction end of the carburetors. Normally, this form of air intake device also incorporates some form of silencing arrangement in the form of a tuning tube that extends from a plenum chamber that communicates with the inlet end of the carburetor. Frequently, it is the practice to provide these tuning tubes at the outer peripheral edges of the carburetors and extending in a rearwardly facing direction. However, this form of disposition of the intake devices and their inlets substantially increases the width of the forward portion of the engine, an undesirable result.
It is, therefore, a principal object of this invention to provide an improved and compact induction system for an internal combustion engine.
It is a further object of this invention to provide an improved and compact induction system for an engine that has intake devices that are disposed at an angle.
It is a further object of this invention to provide an improved and compact air intake device for a V-type, two-cycle, crankcase compression internal combustion engine and outboard motor employing such an engine.
In addition to the features as aforenoted, it is also desirable that the intake device provide silencing for the inducted air, as aforenoted. In connection with an outboard motor, since the power head is positioned in close proximity to the operator, it is also desirable to insure that the induction system noises are directed away from rather than toward the operator. It is, therefore, a still further object of this invention to provide an improved silencing arrangement for the induction system of an internal combustion engine as used in an outboard motor.